1. Field of the Invention
The present invention relates in general to the field of information handling system cooling subsystems, and more particularly to an information handling system cooling fan suspension vibration filter.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems are typically built from a large variety of components assembled in a housing that cooperate to process information. Many of the components operate on electrical power, which creates heat as a by-product of normal use. In order for many electrical components to operate properly, excess heated generated by the consumption of electrical power typically is removed from the housing, such as by blowing a cooling airflow through the housing with a cooling fan. Thermal sensors within the housing measure temperatures and provide the sensed temperatures to a cooling fan controller. The cooling fan controller varies the speed at which cooling fans operate so that thermal conditions within the information handling system housing are maintained within defined operational parameters. If thermal conditions become extreme, components can fail due to thermal stress or their life can be substantially shortened. Alternatively, the information handling system can throttle or power down components in order to decrease the amount of thermal energy released in the housing. Although extreme thermal conditions are typically avoided with system cooling fans which can push airflow across a higher static pressure, the higher rotational speed for these fans tend to have louder acoustics, generate more vibration and consume more power consumption.
Generally, information handling systems operate with minimal acoustics since many of the electrical components used to build information handling systems which generate heat make use of heat sinks or require lower airflow volumes to keep them cool. Cooling fans represent the most significant source of acoustics in a typical information handling system. Loud acoustics during times of thermal stress due to high fan speed operations can distract information handling system end users. In addition, high fan speed acoustics and related cooling fan vibrations can result in damage to information handling system components. For example, vibrations generated by a cooling fan sometimes transfer to electrical components causing physical damage to the components over time. One example of such damage is breaking or cracking of motherboard connections to electrical components, such as solder that holds pins of electrical components in place. Another example of such damage is wear and reduced performance of hard disk drives due to vibration that transfers to the rotating magnetic storage disk found in typical hard disk drives.
One technique used by information handling system manufacturers to minimize the impact of cooling fan vibrations on acoustics and on operation of other components is to install dampers at coupling points that hold a cooling fan in place. For example, rubber or plastic grommets install at the positions where screws or bolts couple the cooling fan to the information handling system chassis, such as the corners of the cooling fan with an interface directly to the fan carrier or the fan bay itself. The amount of damping depends upon the type of material used for the grommets and provides dampening across the frequency spectrum of vibrations associated with cooling fan operations by absorbing energy at the point of support of the cooling fan. Isolation of cooling fan vibrations with grommets is only capable of reducing amplitudes in limited frequency ranges, with generic dampening across that limited frequency range, without regard to the impact that vibrations in a particular frequency range have on information handling system operations.